鸡传染性支气管炎病毒(IBV)H120疫苗株S1基因的克隆与序列测定

根据国外已发表的鸡传染性支气管炎病毒(IBV)S1基因序列设计了一对引物,通过RT-PCR特异性扩增出IBV H120疫苗株的S1基因,产物大小为1.62 kb,与设计相符.同源性比较结果显示,H120株与H52、M41和BEAU株的S1基因核苷酸序列的同源性分别为97.1 %、96.9 %和96.8 %,表明IBV H120疫苗株与标准毒株的S1基因具有高度的同源性.     

鸽源冠状病毒PSH中国分离株S1基因克隆及分子进化分析

对分离鉴定的鸽源冠状病毒PSH株纤突蛋白S1基因进行RT-PCR法扩增、克隆和序列测定分析.结果表明其S1基因由1 626个核苷酸组成,编码541个氨基酸,S蛋白的切割识别位点为精氨酸-精氨酸-苯丙氨酸-精氨酸-精氨酸（RRFRR）,与常见的鸡传染性支气管炎病毒（IBV）S蛋白切割识别位点相似（RRF/SRR）.该病毒与火鸡蓝冠病病毒（TCV）Gh、G1株S1基因推导的氨基酸同源性仅为24.7%、25%,而与IBV H52、H120、M41、Beau、Conn、Gray、Hotel、SH1、SH2、SH5、SH6基因推导的氨基酸同源性在75.0%～99.6%,其中与SH2、SH5的氨基酸同源性更是达到了99.6%,进一步证明该冠状病毒可能来源于IBV.     

鸡传染性支气管炎病毒分离鉴定及S1基因遗传演化分析

为调查辽宁地区鸡传染性支气管炎病毒(IBV)的流行及遗传演化情况,从辽宁某鸡场疑似鸡传染性支气管炎病料中分离得到1株病毒,经分子生物学检测、鸡胚矮小化试验、新城疫病毒血凝特性干扰试验和动物回归试验,确定该毒株为IBV,并命名为CH/LN/2019。扩增该毒株S1基因并进行序列分析发现,分离株S1基因全长1 620 nt,编码540个氨基酸,S1蛋白裂解位点为HRRRR,属于基因Ⅰ型(QX型)毒株;同源性比对发现,分离株与基因Ⅰ型代表毒株QXIBV株的核苷酸和氨基酸序列同源性最高,分别为95.6%和94.8%;与国内常规型疫苗H52、H120和Ma5毒株的同源性较低,核苷酸和氨基酸序列同源性仅为77.2%~76.9%和75.4%~76.2%。本试验为辽宁地区鸡传染性支气管炎的流行病学调查及免疫防控提供了参考。     

鸡传染性支气管炎病毒M41、4/91及疫苗株Ma5、H52、H120 N基因的克隆与序列分析

参照IBVN基因序列,设计一对引物通过RT-PCR扩出IBV标准强毒株株M41,传支变异株4/91和疫苗株Ma5、H52、H120的N蛋白基因序列,基因产物大小为1.23kb。序列分析结果表明,M41株与Ma5、H52、H120的核苷酸序列推导的氨基酸序列的同源性为92.2%～92.9%,而经4/91与M41、Ma5、H52、H120的核苷酸序列推导的氨基酸序列的同源性为91.2%～92.0%,结果表明这几个毒株N基因是相对保守的。     

两株鸡传染性支气管炎病毒的分离鉴定及S1基因序列分析

为调查广东地区鸡传染性支气管炎病毒(IBV)的流行及其遗传变异情况,本研究通过病料SPF鸡胚接种和鸡胚尿囊液的RT-PCR鉴定,于2013年从广东湛江地区不同发病鸡场分离到两株IBV,分别命名为CK/CH/GD/ZJ10/2013和CK/CH/GD/ZJ11/2013,并对这两株IBV的S1基因进行序列分析。结果显示,CK/CH/GD/ZJ10/2013株S1基因全长1 626 bp,编码542个氨基酸,其裂解位点为NRFRR,属于基因型Ⅲ,并推测其为基因型Ⅲ毒株(CK/CH/GX/NN11-3)与基因型Ⅰ毒株(GX-NN-6)在S1基因处发生重组而产生的新毒株;CK/CH/GD/ZJ11/2013株S1基因全长1620 bp,编码540个氨基酸,其裂解位点为HRRRR,属于基因型Ⅰ(类QX型);两株IBV的S1基因间核苷酸序列及其推导的氨基酸序列同源性较低,与位于同一基因型的参考毒株间同源性较高,而与中国使用的Mass型常规疫苗H120和H52之间的同源性最低,仅为75.7%~76.3%和77.1%~77.9%。本研究可为广东省IBV的流行病学调查和分子生物学研究提供参考。     

传染性支气管炎DN-1分离株S1基因的克隆与序列分析

根据已发表的鸡传染性支气管炎病毒(IBV)S1基因序列设计了1对引物,通过RT-PCR特异性扩增出DN-1株的S1基因,产物为1.7 kb,与设计相符.同源性比较结果显示,DN-1株与H52、H120株的S1基因核苷酸序列的同源性分别为99.7%、99.2%,表明IBV DN-1分离株与疫苗株的S1基因具有高度的同源性.     

新疆1株鸡传染性支气管炎病毒的分离鉴定及S1基因序列分析

为了解乌鲁木齐市鸡传染性支气管炎(IB)的流行特征，本研究利用鸡胚培养、RT-PCR、新城疫病毒(NDV)干扰及鸡胚半数感染量(EID₅₀)测定等多种方法分离到一株鸡传染性支气管炎病毒(IBV),将其命名为IBV/CK/CH(XJ)/01/2020。对其S1基因进行序列测定及比对分析发现，该分离株在鸡胚上连传5代出现侏儒胚现象，并且可以抑制NDV在鸡胚中的增殖，经计算其EID₅₀为10^-4.58/0.1 mL,为中等毒力毒株，攻毒组与正常组比较，雏鸡气管内有大量黏液且肺脏肿大，表现为呼吸型毒株特征，且其S蛋白裂解位点序列为HRRKR,与TC07-2、GX-NN0903等毒株形成一个独立的发育进化群，均属于TC07-2/GVI-1型IBV;与国内常用的H120、H52、M41等疫苗株的同源性仅为59%～65%。本研究为新疆地区IB的流行病学提供参考，也为当地IB的防控提供了理论依据。     

鸡传染性支气管炎病毒GZ株的分离鉴定及3CL~(pro)基因片段序列分析

从福建某鸡场发病鸡的气管和肾脏组织中分离到1株病毒,通过病毒对SPF鸡胚的致病性特征、血凝特性、电镜观察及RT-PCR鉴定等方面的研究,证实该病毒为鸡传染性支气管炎病毒(IBV),并命名为GZ毒株。通过RT-PCR对该毒株的3CLpro基因片段进行扩增,随后进行克隆与测序。该序列与参考毒株的核苷酸序列分析显示,GZ株的3CLpro基因片段与参考毒株的同源性为85.9%~98.5%,与Beaudette毒株核苷酸序列同源性最高(98.5%),而与H120株同源性为89.7%,与LX4株同源性最低(85.9%)。遗传演化分析显示,GZ分离株与参考株可以划分为3个群,GZ分离株与Beaudette毒株处于同一分支,而与LX4、BJ及Massachusetts毒株亲缘关系较远。     

鸡传染性支气管炎病毒(IBV)H120疫苗株S1基因的克隆与序列测定

根据国外已发表的鸡传染性支气管炎病毒(IBV)S1基因序列设计了一对引物，通过：RT-PCR特异性扩增出IBV H120疫苗株的S1基因，产物大小为1．62kb，与设计相符。同源性比较结果显示，H120株与H52、M41和BEAU株的S1基因核苷酸序列的同源性分别为97．1％、96．9％和96．8％，表明IBV H120疫苗株与标准毒株的S1基因具有高度的同源性。     

鸡传染性支气管炎病毒TJ9602、HN9604、BJ9601分离株特性的研究

从天津、河南、北京的鸡场分别分离到TJ9602、HN9604、BJ9601鸡传染性支气管炎病毒毒株,对其进行了动物回归、生物学特性、理化特性、血清学试验、抗原定位,对分离株的S1基因进行了RT-PCR扩增、核酸序列分析等研究.确定3株分离毒株为致肾病变的IBV,亲嗜器官为肾脏.HN9604和BJ9601与M41和H120均有较强的中和抗原交叉反应性,S1基因同源性分析,HN9604和BJ9601 S1基因与H120毒株的同源性最高,与H120毒株同属于A分支,均属于Ⅰ群.U9602与H120、M41等参考毒株的中和抗原交叉反应均较低,S1基因同源性分析,属于Ⅱ群.     

癸氧喹酯干混悬剂含量测定的改进

采用高效液相色谱法测定癸氧喹酯干混悬剂的含量,在2-250μg/mL范围内,峰面积的常用对数与进样量浓度的常用对数呈良好的线性关系,R^2=1(n=5),平均回收率为99.24%~99.51%,RSD在0.05%~0.28%。此方法分析时间短,样品前处理简便、定量结果准确,重现性好,结果满意,为其质量控制提供了依据。     

商会自治的基石——商会自治规范研究

在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。     

猪毛色遗传的研究进展

本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。     

中华人民共和国农业部公告 第267号

为贯彻落实《兽药生产质量管理规范》(简称《兽药GMP》),进一步推动兽药GMP实施进程,我部制定了《兽药生产质量管理规范检查验收办法》,现予公告。本公告自2003年6月1日起施行。附件:兽药生产质量管理规范检查验收办法二○○三年四月十日第一章 总则 第一条 为推动《兽药生产质量管理规范》(以下简称兽药GMP)的实施,规范兽药GMP检查验收工作,制定本办法。 第二条 农业部负责全国兽药GMP管理和检查验收工作;负责制修订兽药GMP检查验收管理规定;负责兽药GMP检查员队伍建设和监督管理工作,负责国际兽药贸易中GMP互认工作。 …     

鸡败血支原体垂直传播模式及其阻断方法

以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。     

Comparison of 2 methods of centesis of the bursa of the biceps brachii tendon of horses

REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air.     

不同样本商品蜂蜜中硒含量的测定

用硝酸和高氯酸消化蜂蜜,使硒游离出来,在微酸性环境下,硒和2,3-二氨基萘(DAN)生成有较强荧光的物质,用环己烷萃取,在激发波长378nm,荧光波长518nm处测定其荧光强度。蜂蜜中硒含量范围:0.10～0.82μg/g。表明:蜂蜜应视为天然富硒营养品。     

乳酸杆菌益生作用机制的研究进展

乳酸杆菌作为益生菌广泛用于人和动物。本文综述了乳酸杆菌改善宿主健康的机制。乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道。文章重点讨论了乳酸杆菌表面成分（表面蛋白、脂磷壁酸和肽聚糖）与肠道受体（Ｃ型凝集素受体、Ｔｏｌｌ样受体和 Ｎｏｄ样受体）,阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制。     

Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF

Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo.